反应详情

温度

-78 °C

At 0° C., 0.1 mol of DCC, dissolved in methylene chloride, is added to a mixture of 0.1 mol of 4'-heptyloxy-2,3-difluorobiphenylcarboxylic acid (preparation: 0.1 mol of 2,3-difluoro-4'-heptyloxybiphenyl and 0.1 mol of TMEDA are dissolved in 200 ml of THF, and the solution is cooled to -78° C. and reacted at this temperature with 0.105 mol of a 1.6N solution of BuLi in hexane. The reaction mixture is stirred at -78° C. for 3 hours and then tipped in one portion onto 200 g of powdered dry ice. After customary work-up, 4'-heptyloxy-2,3-difluorobiphenyl-4-carboxylic acid is obtained), 0.1 mol of optically active 2-cyano-2-methylhexan-1-ol (which can be prepared from optically active ethyl 2-methyl-2-butylcyanoacetate by reduction using LiBH4) and a catalytic amount of 4-N,N'-dimethylaminopyridine (DMAP) in 200 ml of methylene chloride. The mixture is subsequently stirred at room temperature for 12 hours and worked up in a customary manner, and the product is purified by crystallization, to give optically active 2-cyano-2-methylhexyl 4'-heptyloxy-2,3-difluorobiphenyl-4-carboxylate.

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